Method for fabricating honeycomb insulating material

ABSTRACT

Apparatus for mass producing one or more individual stacks of expandable, secured together tubular strips which includes a stacking station having an inlet and a conveyor system for sequentially delivering tubular strips having a flat face sequentially to a point opposite said inlet. The stacking station includes pushing apparatus opposite said inlet for pushing the strip delivered opposite said inlet into said chamber. The pushing apparatus has a strip-holding face lying in a given plane and having suction apertures for holding said flat face of each strip delivered thereto in said plane. The pushing member is moved back and forth into and out of said stacking chamber at said inlet with said strip-holding face presented parallel to the flat face of the previous strip delivered to said stacking chamber to push the opposite side of the strip against the flat face of the adjacent strip in said chamber to secure the strips together and form a substantially unwrinkled stack of aligned strips.

This is a divisional of U.S. application Ser. No. 07/839,600 filed onFeb. 21, 1992 now U.S. Pat. No. 5,334,275 issued on Aug. 2, 1994.

FIELD OF THE INVENTION

The present invention has its most important application in the massproduction of individual stacks of secured together, flat, flexibleexpandable tubular strips from which expandable honeycomb panels of adesired overall width and expandable length can be cut. Fabricators thenassemble the pleated panels with various hardware, like support railsand pull cords, to form the completed assembly which is installed in theuser's homes to cover windows and other openings.

The present invention in its most preferred form deals with a method andapparatus for receiving a web forming a continuous, expandable flattube, and by a unique combination of adhesive-applying and stackingoperations, and unique control and stacking apparatus, efficiently andreliably produce and package stacks of secured-together, together, flat,flexible expandable tubular strips.

BACKGROUND OF INVENTION

Various methods and apparatus have been heretofore developed for makingsaid expandable honeycomb panels. Most, if not all, of these methodsleave much to be desired from the standpoint of production efficiency.

Dutch Application Serial No. 6706563 of Landa, published Nov. 11, 1968discloses the formation of such a panel from a number of narrow webs ofthermoplastic material each of which are unwound from a roll in anunfolded state. The longitudinal edges of each web are tightly foldedover, an end strip of a given length is then severed from each web, andthe severed strips are then simultaneously superimposed. Thesuperimposed strips are then welded together to form an expandablehoneycomb panel.

U.S. Pat. No. 3,493,450 to Judge, Jr. discloses a method of makingexpandable honeycomb panels by applying laterally extending bands ofadhesive to a web of sheet material and cutting individual strips fromthe web. A vacuum pick-up device picks up the severed and adhesivecoated strips of material and sequentially delivers the individualstrips above a stacking station where they are stacked one upon theother. In the process of being stacked, the adhesive adheres theadjacent strips together to form an expandable honeycomb panelstructure. The completed honeycomb structure is then cut into narrowstrips of a desired width to form expandable honeycomb panels.

U.S. Pat. No. 4,450,027 to Colson discloses another method and apparatusfor making expandable honeycomb insulation panels. Like the methoddisclosed in the Judge, Jr. Patent, the Colson method starts with acontinuous web of unfolded material and, like the method disclosed inthe Landa published application, progressively folds over the oppositelongitudinal edges of the web. The Colson method then applies acontiguous band of adhesive to one side of the web. The adhesive-coatedcontinuous web, unlike the method disclosed in the Landa and Judge, Jr.prior art, is continuously wound on a rotating stacker. The wound web isremoved from the stacker and cut into separate stacks of a desiredlength.

The present method and apparatus to be described produces in a veryefficient and reliable manner, and, in the most preferred form of theinvention, monitored and packaged, individual stacks of expandablehoneycomb material, and without infringing known patents of others.

SUMMARY OF THE INVENTION

The present invention preferably starts with a single web or sheetforming a continuous flat tube or tubular web. The flat tube could beformed in any manner for the purposes of the present invention. Anadhesive is preferably applied to the web in one or more discontinuousbands running longitudinally of the web, although in accordance withbroadest aspects of the invention, it could less desirably be applied tothe strips after being cut from the web. The adhesive coated web issequentially cut into strips, and then sequentially stacked in a uniquemanner which is completely different from that carried out in all of theaforesaid described prior art methods.

The preferred form of the present invention, like a bottom stackingsystem disclosed in copending application Ser. No. 07/773,843, filedOct. 7, 1991, entitled "Method and Apparatus for Fabricating HoneycombInsulating Material" filed in the names of Kay L. Ruggles, Cary L.Ruggles, Bryan K. Ruggles, Kerry Strauss and Dennis Buehner, includes avertical stacking chamber positioned above an inlet station. Theelevated bottom floor of this chamber has a longitudinally extendingstrip pass-through slot which is narrower than the width of the stripsto be delivered thereto and of a length to receive each strip. Eachstrip, preferably coated with adhesive along the central region thereof,is delivered one at a time at spaced time intervals to a positionbeneath this slot. Each strip is then pushed up through this slot andagainst the bottom face of the strip in the chamber above it, where itis bonded to this strip. While the defining walls of the slot could bedefined by a pair of spaced resilient strips which flex as the narrowermore rigid yet flexible strips are pushed thereby, it is preferablydefined by spaced rigid walls, so that each flexible strip bows upwardlyas it is pushed through the slot.

Good bonding of all the strips to be stacked is achieved by providingboth an upward and downward force on the strips in the stacking. Theupward force is achieved by pushing the new strip into the stackingchamber to a degree which raises the strips above it. The downward forcecan be achieved by a weight bar placed in the chamber which isprogressively raised by the strips being stacked in the chamber belowit. When the chamber is full, the bar and the stacked strips are removedfrom the chamber.

In accordance with an improvement in this aspect of the invention, thedownward force on the strips in the stacking chamber is achieved by theweight of the strips in the stacking chamber which continuously deliversthe strips from the top thereof, preferably onto a downwardly andforwardly inclining back-lighted translucent wall. This back-lightedwall allows the operator to monitor the slightly expanded strips fordefects. Defective strips are cut away by the operator. This inclinedwall merges with a vertical guide wall which directs the monitoredstrips into the opened top of a box which is the packaging used to shipthe product produced by the present invention to the fabricators ofexpandable honeycomb panels.

Prior to this basically new bottom stacking technique just described andclaimed in said copending application Ser. No. 07/773,843, the onlyprior art bottom stacking systems known to applicants which stack piecesof material from the bottom of the stack did so with pieces of rigidsheet material. When these rigid sheets are delivered to the inlet of astacking station, they engage a vertical abutment which aligns thepieces and makes it readily possible to stack successive pieces from thebottom of the stack. Examples of this prior art are the stacking systemsshown in U.S. Pat. No. 3,866,765 to Stobb and U.S. Pat. No. 3,834,290 toNelson. (Such an abutment wall is not suitable for stacking the flexiblestrips used to make honeycomb panels.)

The preferred form of the invention described and claimed herein usesapparatus for pushing the flexible strips up through the narrower slotin the bottom of the stacking chamber in a completely different mannerthan that disclosed in copending application, Ser. No. 07/773,843. Asthere disclosed, the strips are preferably delivered below the strippass-through slot of the stacking chamber by a pair of laterally spacedsuction conveyor belts. A narrow raisable pusher bar is mounted to passbetween the belts and through the slot in the floor of the stackingchamber, to push the strip held by suction on the belts off the beltsand into the stacking chamber. Because there is no fixed connectionbetween the pusher bar and the strip, to obtain proper lateral alignmentof the strips in the stacking chamber disclosed in this pendingapplication, it was found helpful as a practical matter that the bottomof the stacking chamber be defined by a pair of vertical confrontingwalls which are spaced apart a distance slightly greater than the widthof the strips. These walls thus laterally align each strip being pushedinto the stacking chamber with the strip above it.

Also, to avoid waviness in the stack of secured together strips producedin the stacking chamber, it was found necessary in the equipment shownin this pending application that each of the strips be adhesivelysecured to some strip above it along substantially one or morecontinuous adhesive bands. When using such a pusher bar, it was foundthat it was not practical to form separable stacks of strips in thestacking chamber since, in such case, the uppermost strip in each stackcould not be secured to the bottom face of a strip of the stack aboveit, and thus it could sometimes assume an uneven configuration whichaffected the strips below. To eliminate this problem in the equipmentdisclosed in this pending application, the first strip to be stacked inthe stacking chamber is there secured to a rigid strip placed in thestacking chamber just below the weight bar, before the stacking of theflexible strips begins. As a practical matter, all strips in the chamberare here secured together and so separable stacks of strips are notformed in the stacking chamber. These must be formed by cuttingindividual stacks of strips from the continuous stack of securedtogether strips after removal of the weight bar and the stack of stripsfrom the stacking chamber.

In accordance with one of the features of the present invention, toovercome these problems and to make it readily possible to formseparable stacks in the stacking chamber, each strip delivered to theinlet of the stacking chamber is raised into the stacking chamber andpushed against the strip above it by a pusher means which retains thestrip to it by suction force. Therefore, the upper face of every stripwhich is pushed against the strip above it in the stacking chamber islaterally aligned by this pusher means and presents a perfectly flathorizontal surface as it is pushed against the strip above it by virtueof the suction force which draws the strip against the flat face of thispusher means.

The separation of this pusher means from the strip pushed into thestacking chamber thereby is achieved as the pusher means is lowered fromits raised position and passes down through the slot in the bottom ofthe stacking chamber. The strip separates from the pusher means as it ispulled against the floor of the chamber by the pusher means. The floorholds the strip against further downward movement with the pusher means.The suction force must, of course, be initially adjusted so as to beinsufficient to pull the flexible strip back through the slot.

In the preferred from of the present invention, the pusher means is asingle apertured endless conveyor belt which delivers the strip to thestacking chamber inlet. The belt is sufficiently narrow to be passablethrough the narrow slot in the floor of the stacking chamber. When thebelt delivers a strip opposite the inlet to the stacking chamber, itslongitudinal movement is stopped and support structure for the belt israised to push the strip carried thereby into the stacking chamber.

Other features of the invention deal with the adhesive-applyingapparatus and the pattern in which said adhesive is applied whereseparable stacks of strips are to be formed in the stacking chamber. Onevery important feature of the adhesive-applying apparatus is that,instead of using what is conventionally a circular discharge port, thedischarge port is rectangular in shape with the longitudinal edges ofthe slot parallel to the direction of movement of the web and to thelongitudinal edges of the web. Such a discharge port deposits anadhesive bead of a desired consistent thickness and produces a band ofadhesive with perfectly parallel precisely located edges. Whilerectangular adhesive discharge ports have been used for depositingrectangular beads of adhesive, to the knowledge of the applicants, suchports have not been used to deposit continuous bands of adhesive,especially in the manufacture of expandable honeycomb panels.

As previously indicated, while the adhesive could be applied to thestrips after they are severed from a continuous web, it is mostadvantageously applied to the top of the web before the strips are cuttherefrom. If the adhesive were applied to the strips after they havebeen severed from the web, the adhesive applicator must be turned on andoff quickly as the short strips pass thereby, so that adhesive will notdrip in the gaps between the strips. It is very difficult if notimpossible to avoid some spill-over into these gaps if the web is movedby the applicator at a speed to achieve practical productionefficiencies.

In accordance with another aspect of the invention, the adhesive isapplied as discontinuous bands in a pattern related to the problems inthe prior art of adhesive dripping from the adhesive discharge portsafter adhesive flow thereto is terminated by the close of the valve, andto variations in adhesive consistency due to variation in itstemperature when it is deposited on the web. Thus, where the stackingchamber is to contain separable stacks of strips of a length L, theadhesive applicator means is shut off when widely spaced web segmentseach of a length L pass the adhesive applicator means and which are toconstitute the first strip in the various secured together stack ofstrips to be formed in the stacking chamber. The adhesive-free firststrip in each stack desirably will not then stick to the strip above it.In the most preferred form of the invention, to avoid production ofadhesive-free strips to be stacked with undesired spill-over of adhesivethereon, the adhesive applicator means is initially shut off before theportion of the web passes thereby which is to form the firstadhesive-free strip in a stack, so that one or more segments of a lengthL of the web pass thereby are formed as throw-away strips prior to thebeginning of a strip stacking operation and following the stacking ofthe last strip of each separable stack. These one or more throw-awaystrips are not stacked, and so the conveyor belt passing below thestacking chamber inlet is not stopped and raised when these strips aremoved below the stacking chamber.

The need to form at least one throw-away strip is due to the inabilityas a practical matter to instantly cut off all flow of adhesive from theadhesive applicator means as the trailing end of a segment of the webwhich is to form the last strip of each separable stack to be formed inthe stacking chamber passes by the adhesive applicator means. Someadhesive accumulates below the shut-off valve in the applicator head ofthe adhesive applicator means which adhesive continues to drip therefromfor a given interval of time after valve closure. This can undesirablycoat one or more web segments which will form strips to be stacked whichare to be free of adhesive.

Other features of the invention claimed herein and described in thespecification to follow improve the efficiency, set-up convenience, andreliability of the method and apparatus aspects of the invention. Forexample, the efficient fabrication of consistently good qualityexpandable honeycomb panels requires the delivery of adhesive bands ontothe web with the same thickness, width, and consistency. For reasons tobe explained, this is difficult to achieve unless at the initiation ofeach opening of the valve in the adhesive applicator head one or morethrow-away strip-forming segments of the web are generated.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a part of one of the stacks ofexpandable honeycomb insulation material made by the method andapparatus of the present invention;

FIG. 2 is a transverse section through the stack of FIG. 1, taken alongsection line 2--2 therein;

FIG. 3 is a block diagram showing the basic process steps and apparatuselements of the present invention;

FIG. 4A is a front elevational view of the preferred embodiment of theinvention from the web reel support portion to the first high speedconveyor portion thereof which feeds strips cut from the web to a secondconveyor located below the stacking chamber;

FIG. 4B is a front elevational view of the preferred embodiment of theinvention which is a continuation of FIG. 4A and includes the secondconveyor positioned below the stacking chamber and shown also in thestacking chamber and structure which raises and lowers the secondconveyor;

FIG. 5 is an enlarged plan view of the portion of the apparatus shown inFIG. 4A which includes the web reel supporting structure and tensioncontrol and web aligning apparatus following that structure;

FIG. 6 is an elevational view of the apparatus shown in FIG. 5;

FIG. 6A is a perspective view of the folding apparatus used in thepreferred form of the present invention to fold over the longitudinaledges of the web and which is located following the portion of theinvention shown in FIGS. 5 and 6;

FIG. 7 is a top plan view of the portion of the apparatus shown in FIGS.4A and 4B which includes a heating drum, pressure rollers which pressthe previously folded web upon the heating drum, a cooling tablefollowing the heated drum and adhesive applicator apparatus whichapplies adhesive to the folded web passing over the cooling table;

FIG. 8 is a front elevational view of the apparatus shown in FIG. 7;

FIG. 9A is an enlarged plan view of the cooling table shown in FIGS. 7and 8 as seen in viewing plane 9A--9A shown in FIG. 8;

FIG. 9B is a fragmentary vertical sectional view through the apparatusshown in FIG. 9A, as seen in viewing plane 9B--9B in FIG. 9A and showsthe tip of an adhesive applicator head applying adhesive to the top ofthe web passing over the cooling table;

FIG. 9C is a bottom plane view of the adhesive discharge ports as seenin viewing plane 9C--9C in FIG. 9B;

FIG. 9D is a fragmentary longitudinal sectional view through the coolingtable behind the first adhesive applicator head and showing a heatsinking block riding on the folded web;

FIG. 10 is a plan view of the cutting apparatus which follows theadhesive-applying and cooling apparatus shown in FIGS. 7, 8, 9A and 9B;

FIG. 11 is a front, elevational view of the apparatus shown in FIG. 10;

FIG. 12 is a vertical, sectional view through the apparatus shown inFIG. 11, as seen in viewing plane 12--12;

FIG. 13 is a vertical, sectional view through the apparatus shown inFIG. 11, as seen in viewing plane 13--13;

FIG. 14 is a sectional view through the apparatus shown in FIG. 13, asseen in viewing plane 14--14;

FIG. 14A is a sectional view showing the cutting apparatus in theprocess of cutting through a web passing over a driven roller;

FIG. 15 is a plan view, partially broken away, of the first conveyorwhich delivers strips from the cutting apparatus to the second conveyorlocated beneath the stacking chamber;

FIG. 16 is a front, elevational view of the apparatus shown in FIG. 15;

FIG. 17 is a vertical sectional view through the apparatus shown in FIG.16 as seen in viewing plane 17--17, and illustrates the manner in whicha vacuum pump inlet tube is connected to portions of the equipment whichdirects suction pressure to the upper section of an endless conveyorbelt or chain of the first conveyor;

FIG. 18 is a horizontal sectional view through the end of the firstconveyor shown in FIG. 16, as seen in viewing plane 18--18 therein;

FIG. 19A is a broken away plan view of the portion of the apparatusshown in FIGS. 4A and 4B which includes a portion of the stackingchamber and the second conveyor which is raisable into the stackingchamber;

FIG. 19B is an extension of the apparatus shown in FIG. 19A and showsthe remainder of the stacking chamber and second conveyor;

FIG. 20A is a front elevational view of the apparatus shown in plan viewin FIG. 19A;

FIG. 20B is a front elevational view of the apparatus shown in plan viewin FIG. 19B;

FIG. 21 is a vertical sectional view through the apparatus shown in FIG.20A as seen in viewing plane 21--21 therein and shows the portions ofthe apparatus which deliver suction pressure to the upper section of theendless conveyor chain which delivers strips to the stacking chamber andportions of the stacking chamber and the endless conveyor chain of thesecond conveyor;

FIG. 22 is a vertical sectional view through the stacking chamber andbelt conveyor as seen in viewing plane 22--22 in FIG. 21;

FIG. 23 is a vertical sectional view through the stacking chamber,second high conveyor and the conveyor lifting apparatus as seen inviewing plane 23--23 in FIG. 20A;

FIG. 23A is an enlarged fragmentary vertical sectional view through thestacking chamber and the second conveyor and shows in solid lines theupper section of the endless conveyor chain of the second conveyorraised partially to push the first strip into the stacking chamber andin dotted lines the chain when it is raised to its narrow height;

FIG. 23B is a view corresponding to FIG. 23A when a number of stripshave been pushed into the stacking chamber and the second conveyor asshown in sold lines has been lowered to its normal position below thestacking chamber the figure showing in dashed lines;

FIG. 24 is a front elevational view, partly broken away as seen inviewing plane 24--24 shown in FIG. 23;

FIGS. 25A-G considered together is a program flow diagram illustratingthe manner in which the equipment shown in the drawings is operated andcontrolled from the various sensors shown therein; and

FIG. 26 is a perspective view of a modified stacking chamber andassociated monitoring station constituting the most preferred form forthe stacking station of the invention.

DESCRIPTION OF PREFERRED Exemplary Forms of the Invention FIGS. 1 and2--Product Made By the Present Invention

FIG. 1 is a perspective view of a part of one of the stacks 3 ofexpandable honeycomb insulation material made by the method andapparatus of the present invention, where the expandable honeycombmaterial is of the form disclosed in Dutch application Ser. No.6,508,988 of Landa, published Jan. 13, 1967. As shown in FIG. 1 herein,the stack 3 is made up of individual folded strips 4 of flexiblematerial each forming a flattened, expandable tube when secured to thenext strip by bands 6--6' of adhesive shown in FIG. 2. The strips asillustrated are preferably formed from an initially unfolded web of asuitable flexible thermoplastic polyester or similar material used tomake expandable honeycomb panels which cover windows and the like. Theopposite longitudinal edge portions of the strip are preferably foldedover at 4c--4c' in any desired way into contiguous but spaced relationto form permanently tightly folded over panels 4b--4b' overlying abottom panel 4a. The strips 4 are cut from this web preferably after thebands 6--6' of adhesive are applied to the top portion of the web whichis to form all but the first strip in the stack. The bands 6--6' ofadhesive are applied only to the confronting end portions of the foldedover panels 4b--4b'.

As previously indicated, the features of the present method andapparatus invention are applicable to tube-forming strips formed in waysother than by a folding process. Thus, for example, the panels 4b--4b'could constitute a single integral panel which is secured together to aseparate panel of the same width at the opposite longitudinal margins ofthese panels. In either case, individual tube-forming stripsare-adhesively secured together and stacked in the unique mannerpreviously described.

FIG. 3--Basic Block Diagram of the Invention

FIG. 3 illustrates in block form the basic method steps and apparatuselements used in the preferred form of manufacturing the stack 3 shownin FIGS. 1 and 2. A support structure is provided for preferablysupporting two reels 12A--12A' holding webs of flexible polyester orsimilar material to form honeycomb panels. The web of the bottom reel12A' is identified by reference numerals 13'. Only one of the reels 12Aor 12A' is unwound at any time and passes through the apparatus to bedescribed. When one of the reels has been used up, the leading edge ofthe web of material wound on the other reel is spliced to the end of thecompletely unwound web by a suitable splicing tape, splicing thread orstaples. Frequently, the web on the reels 12A--12A' have splicestherein. Splices portions of the web which are located in strips cutfrom the web are automatically disposed of and are not stacked in thestacking chamber to be described.

As illustrated, the unfolded continuous web 13 or 13' of the roll 12A or12A' is fed to conventional web tension and aligning means 11. The webis then fed to folding means 14 which folds over the oppositelongitudinal edge portions of the web to form the configuration of thefolded strips 4 shown in FIGS. 1 and 2. The folded web is thenpreferably fed first to adhesive applying means 16 having the uniquerectangular, adhesive discharge ports previously referred to, and thento cutting means 18 which cuts individual tube-forming strips from theweb. As previously explained, the adhesive applying means appliesadhesive bands to the spaced inner end portions of the folded over webedge portion in a preferred discontinuous pattern.

This discontinuous pattern produces separable stacks of secured-togetherstrips in the stacking chamber, each stack comprising a number of stripsN of a length L. When a stacking mode of operation is in effect, theadhesive applicator means is turned on and off in a repetitive patternwhich produces a to-be-stacked first adhesive-free strip at thebeginning of each stack, also preferably ahead of the latter strip ato-be-stacked adhesive-free separator strip, and N-1 adhesive coatedstrips following the former first strip.

To avoid the overlap of adhesive onto the first strip of each stack ofstrips to be stacked in the stacking chamber to be described, because ofundesired dripping of the nozzles of the adhesive-applying means, aspreviously indicated this pattern also produces at least one, andpreferably three, adhesive-free throw-away strips ahead of the twoabove-mentioned to-be-stacked adhesive-free strips. These throw-awaystrips are not stacked in the stacking chamber.

Also, following the insertion of the adhesive-free separator and firstadhesive-free strip of each stack at least one, and preferably threeadhesive-coated, not-to-be-stacked strips are produced, to assure aneven continuous bead of adhesive on the strips subsequently to bestacked for reasons now to be explained.

The present invention preferably utilizes commercial thermosetting resinadhesive applying equipment where the resins are pre-heated to a desiredtemperature and deposits adhesive on the web in a consistent pattern andthickness and which partially sets to a desirable extent before thestrips are removed from the stacking chamber. This commercial equipmentgenerally has heating elements at the adhesive discharge nozzle of theadhesive applicator means and also along the conduit which delivers theadhesive to the nozzle from a supply source thereof. The temperature andthus the consistency of the adhesive is affected by the length of timethe adhesive remains in the nozzles and the feed conduit. Therefore,adhesive which remains in the feed conduit behind a nozzle closed toproduce adhesive-free strips could heat up to a higher temperature andhave a different consistency from that of the adhesive which flows fromthe nozzle a few seconds later and which was not in a stationary statein the heated feed conduit. Accordingly, each time an adhesiveapplicator valve is opened to permit the initial flow of adhesivetherethrough, the first few strips which are coated with adhesive arethrown away and not fed into the stacking chamber. Of course, thisproblem would not be present where the adhesive applicator nozzles applycontinuous bands of adhesive on the web.

In summary, to avoid any possibility of adjacent stacks of securedtogether strips from stacking together because of dripping adhesive andto assure consistency of the adhesive bands, the adhesive-applying meansis turned on and off in the following repetitive pattern:

(a) Turn-off of the adhesive applying means is initiated as three websegments of a length L pass thereby;

(b) Where, as preferred, an adhesive-free strip is to separate eachstack of strips in the stacking chamber, the adhesive applying means isfurther shut off as the next to-be-stacked two web segments of a lengthL pass thereby;

(c) Turn-on of the adhesive applying means is initiated as the nextthree throw-away web segments, each of a length L pass thereby;

(d) Turn-on of the adhesive applying means is continued as the nextto-be-stacked N-1 segments of the web pass thereby (N being the numberof strips in each secured together stack of strips); and

(e) A new cycle is initiated as the last of the to-be-stacked N-1segments of the web passes by the turned-on adhesive applying meanswhere initiation of the turn off of the adhesive applying means beginsto form three throw away segments.

The web is severed at the beginning and end of each of the web segmentsreferred to and, as previously indicated, the strips formed from thethrown-away segments of the web are not stacked in the stacking chamberto be described.

The adhesive material is preferably an initially liquid polyurethanethermosetting adhesive resin which sets partially in a relatively shortperiod of time so that adjacent strips will be secured together to asufficient degree when removed from the stacking chamber to be describedthat they can withstand the rigors of subsequent handling. The adhesivecures completely over a long period of time to withstand the muchgreater pulling forces when the panel is assembled to support rails andpull cords, mounted over a window or doorway by the ultimate user andthen raised and lowered many thousand times in the useful life of thepanel. Many such adhesives have been used in the prior art. One suitableadhesive is made by H. B. Fuller Company of 1200 Wolters Boulevard,Vadnais Heights, Minn. 55110, purchased from this company under theorder designation NP-2028. When this is the adhesive used, thetemperature thereof when deposited on the web for the exemplary webmaterial described below is preferably 239° Fahrenheit.

Various feed and guide rollers forming a part of the tension and webaligning means 11, folding means 14, adhesive applying means 16 andcutting means 18 constitute conveyor means described in some claims as afirst conveyor section. One unique aspect of the invention is that thesefeed and guide rollers are most advantageously cantilevered rollers sothat when the equipment of the invention is set up for operation, it isan easy matter to apply the unwound portion of the web into positionwhere it extends over the various feed and guide rollers leading to andincluding the cutting apparatus.

The first conveyor section, which may feed the web to the cuttingapparatus at a speed of 250 feet per minute, delivers the individualstrips to a higher speed conveyor means 20 referred to in some of theclaims as a second conveyor section.

The high speed conveyor means operate at a much higher speed than theperipheral speed of the feed rollers associated with the first conveyorsection so that the strips 4 cut from the folded web are conveyed to theinlet station of stacking chamber 22 at spaced time intervals. Thispermits a strip delivered to the inlet of the stacking chamber to bestacked in the vertical stacking chamber 22 by a lifting means 24 whichmoves from an initial lowered position to a raised position and thenreturned to a lowered position before the next strip is delivered to thestacking chamber.

This second conveyor section most desirably consists of a first highspeed conveyor 20A sometimes referred to as an accelerator conveyor. Itis formed by an endless conveyor belt or chain having apertures throughwhich suction force is applied which retains the strips conveyed therebyin a fixed position thereon. This first conveyor is stationary in thesense that it is not raisable. This first conveyor delivers the stripsto a second high speed conveyor 20B also sometimes referred to as astacker conveyor. It also most advantageously comprises an endlessconveyor belt or chain also having apertures through which suction forceis applied which retain each strip as it is delivered to the stackingchamber in a fixed position. The first high speed conveyer operates at asubstantially higher speed than the web is fed through the firstconveyor section to the cutting apparatus 18. The speed of the firsthigh speed conveyor described could be 750 feet per minute and the speedof the second high speed conveyor desirably could be 800 feet perminute.

As described previously, the bottom of the stacking chamber 22 isdefined by a pair of laterally-spaced support shoulders or walls whichform a strip pass-through slot in the floor of the stacking chamber.When the conveyor belt of the second high speed conveyor moves a stripto be stacked in alignment with the slot, the belt movement istemporarily stopped and it is raised through the slot to carry the stripinto the stacking chamber to an extent to raise the stack of stripsabove it. In so doing, the adhesive bands on the top of the strip whichhave not yet completely hardened, are pressed against the bottom panel4a of the strip above it, to better adhere the two adjacent stripstogether. The drying time of the adhesive is sufficient that the stripsare securely adhered by the time each stack of strips is removed fromthe stacking chamber.

When the conveyor belt of the second high speed conveyor is stopped, thesuction applied to the belt continues. It was found, however, thatdepending upon the weight of the strip carried by the belt, there is aslight longitudinal shifting of a strip due to momentum affects when thebelt movement is stopped by the brake. The amount of such shifting isdependent on the weight per given length of the strip and its frictionwith the belt. In the control system shown in the program flow diagramsof FIGS. 25A-25G, depending upon the selected strip material, a varyingbrake operation delay is introduced into the control system so that whena brake-initiating signal is generated upon the second high speedconveyor 20A the delay is determined by the selected web material. Thisinformation is by manual switch operation fed to the system software.Thus, for a heavier per length material, the braking delay period willbe a lesser time than for lighter per length materials.

To aid in the adhesive securement of adjacent strips together in thestacking chamber, a downward force is applied to the top of the stack.This can be achieved by a weight bar in the stacking chamber. When thestacking chamber has been filled, the conveyor system is stopped so thatthe weight bar can be removed and the various stacks of secured togetherstrips manually removed from the chamber.

However, in the preferred form of the invention, a weight bar is notused and the stacking chamber is designed to be automatically emptied.In this case, the desired downward force applied to the stacked stripsto assure optimum adhesive securement thereof is achieved by the weightof the strips above the strip being stacked below. In such case, thefirst group of strips which are stacked in the chamber can be discardedto avoid poorly adhered together strips from being used by thefabricator to form expandable honeycomb panels which are sold to theultimate users thereof.

For reasons previously explained, the operation of the lifting means 24and the braking apparatus which stops movement of the high speedconveyor 20b located below the stacking chamber is disabled where thepreferably first three strips in advance of the first strip of eachstack is moved below the stacking chamber. The braking apparatus andlifting means are also disabled where the preferably three stripsfollowing the first to be stacked adhesive-free strip of each stack aremoved below the stacking chamber. These six strips which are not stackedare thrown off the end of the upper section of the endless conveyor beltforming the second high speed conveyor 20B.

It will be recalled that one of the most important features of thepresent invention is that the lifting means, which preferably is anendless conveyor belt forming part of the high speed conveyor 20b, usesa suction force applied through apertures in the belt to both fix thelateral and longitudinal position of the strip being moved into thestacking chamber and to present a flat, unwrinkled, horizontaladhesive-coated surface to the bottom face of the strip above it whenthe former strip is pushed against the latter strip by the upwardmovement of the belt into the stacking chamber. The lateral dimensionsof the stacking chamber in such case is non-critical. This assures thatthe various successive strips of each stack of strips are adheredtogether evenly to avoid wrinkling of the stack. This produces a veryattractive, high quality, honeycomb panel product.

While the use of a lifting means in the form of a raisable suction beltconveyor is the most preferred form of the invention, a broader aspectof the invention includes the use of a pusher bar with suction holes inthe top surface thereof rather than the conveyor belt as the raisablelifter element. For example, the second high speed conveyor can comprisea pair of laterally spaced conveyor suction belts which are notraisable. The pusher bar is movable between these conveyor belts andthrough the pass-through slot in the bottom of the stacking chamber. Theconveyor belts in such case are preferably not stopped during thestacking operation.

As explained in the introductory part of the specification, the stripsmoved into the stacking chamber are separated from the suction liftingmeans as the lifting means moves down through the pass-through slot inthe bottom of the stacking chamber. The defining walls of the slotretain the strip in place in the stacking chamber as long as the suctionforce involved is not so strong as to pull the strip back through theslot. Obviously, the suction force is adjusted to avoid this undesirableresult. In the application of the invention where the web is theexemplary material to be described, the suction force is preferably -2psi.

As previously indicated, the timing of the operation of the adhesiveapplying means 16, the cutting means 18, the conveyor braking means andthe lifting means 24 is controlled by suitable control means indicatedin the block diagram of FIG. 3 by block 25. Various sensors associatedwith these means which sense the location of the margins of the web arestrips cut therefrom and the positions of parts of these means controlthe operation of various preferably software counters, relays andsolenoids. The detailed manner in which the control means 25 operates isillustrated in the detailed program flow diagrams of FIG. 25A-25G whichare self-explanatory. In the portion of the specification to follow,most preferred forms of the apparatus illustrated by the blocks in FIG.3 will be described.

Reel Support, Tension Control and Web Aligning Apparatus

Referring now to FIGS. 4, 5 and 6, the reels 12A--12A' of web material13--13' are fixed to rotatable shafts 28--28'. The shafts 28--28' areconnected to suitable variable friction brake mechanism 29--29'. Suchmechanism can be purchased from the Electroid Company, 45 Fadem Road,Springfield, N.J. 07081 and sold under Model designation EPB-70-12S-24.These brake mechanisms produce a variable restraining force on therotation of the reel support shafts 28--28' under control of suitablecontrol signals from variable potentiometers responsive to the positionof a dance arm forming part of a web tension control mechanism to bedescribed. This produces a fixed web tension in a manner well known inthe prior art. The operator initially selects the web material on theweb reel 12A or 12A' for use in the equipment shown.

Supported adjacent to a side of the respective reels 12A--12A' atdifferent radial points therealong are combined light source and lightdetecting sensor units PEC-1a and PEC-1a', and PEC-2a and PEC-2a', eachof which directs a beam against the side of the web material on the reelinvolved. The presence of a light reflection signal received by sensorunit PEC-2a or PEC-2a' signals a "ready" condition to the software,indicating the presence of a useable reel.

The other light source and light detecting sensor units PEC-1a andPEC-1a' located closer to the center of the associated reels are used togenerate a signal upon absence of light reflection which results in thesounding of an audible alarm to alert the operator and the appearance ofa prepare-to-change reel command on a suitable display screen (notshown). The operator can then check to see whether the other unused reelis in position on the associated shaft so that he can carry out asplicing operation where the leading edge of the web of the latter reelcan be spliced onto the trailing edge of the web material which isunwound from the active reel.

The unwound web of the selected reel extends down over a guide roller 36and then around tension roller 31 mounted at the end of a dancer arm 30forming part of a tension control system with the function brakemechanism 29. This tension control system may be a well knownelectromagnetic tension control system manufactured by ElectroidCompany, 45 Fadem Road, Springfield, N.J. 07081 and sold under Modeldesignation TC-1. The web passing around the tension roller 31 andpulled by the drive force of a drive roller to be described exerts anupward force on the dancer arm 30. A downward force is exerted on thedancer arm by a pneumatic unit 32 having a piston rod 34 secured to thearm. The movement of the dancer arm controls the operation of a tensioncontrol unit TEN-1 sold by Electroid under Model No. TSS-1. This unitgenerates a signal fed to the brake control mechanism 29--29' exertingan adjustable opposition force to the rotation of the reel shafts28--28'. The tension control unit operates to keep the dancer arm 30horizontal. The downward force of the pneumatic unit 32 is initiallyadjusted to exert a given predetermined force. For example, in thepresent invention where the exemplary strip material is material No.5040 manufactured by the Ashai Company (a strip 0.006 inch thick, 2.25inches wide before it is folded, and having a density of 40 grams persquare centimeter), a 7 pound tension force is applied to the dancer arm30. If the upward pull force on the dancer arm exceeds this force, thedancer arm will move up and a signal will be fed back to the frictionbrake mechanism 29 on the selected reel shaft which will reduce thefriction force of the shaft. This reduces the tension on the web so asto keep the dancer arm 30 in a horizontal position.

If the web extending around the roller 31 should break and not bepresent for any other reason, the dancer arm 30 will obviously drop. Asuitable microswitch or other sensor may be provided to sense thiscondition and generate a signal which will stop operation of theconveyor system and other operating apparatus. In the system disclosed,if the web breaks or the web is completely unwound from the active cellthis signal is generated by a trailing edge-forming photocell PEC-3(FIG. 6).

The web passing around the bottom of the roller 31 passes over idlerrollers 38 and 40. As the web leaves roller 38, it passes between alight source unit PEC-6 which may be multiple infrared LED screenstrobed at a high frequency, and a light detecting sensor unit PEC-6'.The light source unit PEC-6 generates a light beam through the webleaving the roller 38. The light beam passes through the partially lighttransparent web and strikes the light detecting unit PEC-6'. The webwound on the reels 12A and 12A' frequently has a dark splicing tapesecuring together sections of the web. When the light striking thesensor unit PEC-6' is reduced by this tape, the equipment beingdescribed operates in a stacker bypass mode where the strip cut from theweb containing the red splicing tape is not stacked in the stackingchamber, to avoid producing a defective honeycomb panel. The units PEC-6and PEC-6' may be purchased from Banner Engineering in Minneapolis,Minn. under model No. LS-10.

The web leaving the light source and sensor units PEC-6 and PEC-6'passes by trailing edge-detecting sensor unit PEC-3 which generates acontrol signal when a trailing edge of a web passes thereby. This signalwill stop the operation of the equipment and will sound an audiblealarm, alerting the operator that the web on an unused reel should beunwound and spliced to the trailing edge of the web which operated thesensor unit PEC-3. The splice here used will be of sufficient thicknessto actuate a splicing thickness sensor TS-1' located adjacent to thenext roller 40.

If the splicing tape is a thick splicing tape or a splicing thread whichthickens the spliced web at this point, the sensor TS-1' will operatethe equipment in a stacker bypass mode to avoid stacking the stripcontaining the splice involved.

The web leaving the idler roller 40 passes down and then around a pairof horizontally spaced idler rollers 41-43 carried on a frame or housing45. The rollers 41-43 and frame 45 and associated electrical and otherapparatus are commercially available web aligning apparatus which willfix the alignment of the web. This web aligning equipment can bepurchased from the Fife Corporation, 222 West Memorial Road, P.O. Box26508 of Oklahoma City, Okla. 73126. It includes a processor havingModel No. CSP-0106, infrared sensors under Model No. GSE-4, a servotransceiver unit under Model No. 1SCT-03 and an Offset Pivot Guide underModel No. SYMAT-25. It includes a frame or housing 45 mounted forrotation about a vertical axis so that the web can be aligned along afixed longitudinal line.

The rotated position of the frame 45 is controlled by a pair of thesesensors PEC-5 and PEC-5' laterally adjustable and spaced as shown inFIG. 5 which sense the opposite edges of the strip. As long as the lightbeams from both sensors are equally interrupted by these edges, the webis properly aligned. If the light beams of the sensor units becomeunequally interrupted, a control signal is generated which is fed to theservo transducer unit which, in turn, rotates the frame 45 about avertical axis to equalize such interruption. The frame 45 carries theOffset Pivot Guide and the servo transducer unit referred to above whichtogether with the processor referred to obtain this result. The rotationof the frame 45 creates tension in the web which causes it to moveaxially on an idler roller 44 over which the web passes after it leavesthe roller 43.

Unless otherwise stated, the rollers 31, 36, 38, 40 and 44, as well asother rollers to be described, are freely rotatable cantilevered idlerrollers. By cantilevered is meant that the rollers project from theirsupport structures so that the web rides freely thereon without anyguide wall on their outer ends which constrains the lateral positionthereof. There is thus no need to thread the web between flanges orwalls. However, rollers 41-43 are mounted between flanges so that theweb must be threaded around these rollers.

As shown in FIGS. 4A and 6, the reel support structure, and the tensioncontrol and web aligning means are supported on a frame structure 26Awhich is separate from the frame structures 26B, 26C, 26D, 26E and 26Fon which the folding means, adhesive applying means, cutting means andother apparatus are separately supported. With this modularconstruction, the repair or replacement of various portions of theequipment can be more conveniently accomplished.

Folding Means 14 (FIG. 6A)

The folding means 14 can be any suitable folding means utilized in theprior art. However, as illustrated in FIG. 6A, the folding stationincludes first and second pairs of folding rollers 45--45' and 46--46'mounted for rotation about vertical axes and presenting confrontingtapered grooves within which the longitudinal edge portions of the webextend to produce opposite longitudinal folds in the web. The taperingof the confronting grooves of the first pair of rollers 45--45' are lesssteep than that of the confronting grooves in the second pair of rollers46--46', so that the edges of the web are progressively folded around avertically thin, folding plate 48. The plate 48 extends between theconfronting pairs of grooves formed by the rollers 45--45' and 46--46'.The folding plate 48 has rounded edges so that they do not dig into theweb material to form a crease therein. The folding operation iscompleted to form a tight fold by a pair of canted rollers 49--49' whichpress the folded over edge portions of the web upon the top of thefolding plate 48. The web then passes beneath a plate 47 which holds thefolds in their tightly folded condition until it passes around an idlerroller 54 (FIGS. 7 and 8).

To enable the equipment to fold webs of different widths, the variouspairs of rollers 45--45', 46--46' and 49--49' are supported for lateraladjustment on a support base B. The base has slots B1'--B1' throughwhich pass bolts 45a--45a' which are anchored by respective nuts (notshown) beneath the base B. By loosening the nuts, the spacing of theroller pairs 45--45' and 46--46' can be adjusted for folded webs of agiven desired width. As the web width varies, the width of the foldingplate 48 is likewise varied to accommodate the desired width of thefolded web.

The canted rollers 49--49' are supported on an adjustable superstructure49a--49a' which includes horizontal extending rods 49b--49b'. Slidableon these rods are roller support heads like head 49c. These heads havelocking screws like screw 49d extending therefrom which lock thehorizontal adjustment involved. The vertical position of the rollers49--49' can be adjusted in any suitable way. As shown, the rollers arecarried on vertical rods 49e--49e' slidable in gear-containing housingslike 49g--49g'. The vertical elevation of the rollers 45--45' on theserods are roughly and finely adjusted in elevation by adjusting screwslike 49f--49f', and 49h'.

Fold Setting Apparatus

Referring now to FIGS. 4A, 7 and 8, the folded web passing around theidler roller 54 extends around a heated drum 55 carried on a freelyrotatable shaft 55b (FIG. 8.)

The drum 55 is part of an assembly which includes electrical heatingelements which heat the peripheral surface of the drum to a desiredtemperature using suitable temperature control apparatus. This controlapparatus includes a thermocouple 55d which is electrically connected tosuitable control equipment well known in the art. The drum also includeswhat is referred to as an over-temperature snap switch TS-1 whichoperates when the drum temperature exceeds a limited temperature such as400° F. When this switch is operated, a control function is carried outwhich shuts down the entire system being described and sounds an audiblealarm.

The drum assembly is supported by a support structure 55e for movementbetween a dormant lowered position (not shown) and an active raisedposition shown where it will press the web against the idler roller 54and a drive roller 59. The raised position of the drum is sensed by aproximity switch PS-5. The drum support structure 55e is moved up anddown by its attachment to a piston 55f of a solenoid valve controlledpneumatic unit 55g. When the equipment is placed into operation, thelatter solenoid valve is energized to cause the pneumatic unit 55g toraise the drum from its lowered position to its raised position. Theroller 59 is driven by a belt 53 extending between a pulley wheel 53acarried on the shaft 54b and a driven pulley wheel 53b driven by a motor53c. The linear speed of the belt 53 measures the linear speed of theweb moving around the surface of the drum 55.

The operation of the cutting means 18 (FIG. 3) is determined by themount in a cutter control counter which receives count pulses from apulse generator 51 (FIG. 8) which includes a rotatable element 51acontacting the belt 53 so as to be rotated by the belt movement. Thenumber of pulses generated by the pulse generator 51 is thus directlyrelated with the degree of movement of the web through the portion ofthe equipment being described and including the cutting means to behereafter described.

When the web is advanced a distance equal to a desired strip length, thecutter control counter reaches a maximum count and a cut signal isgenerated which operates the cutter apparatus in a manner to bedescribed. The cutter control counter is then reset to zero to start anew cutting cycle. If the equipment is in a stacking mode, then astacking mode counter accumulates a count unless the strip to be cut isa strip with a splice or is one of two strips following thesplice-containing strip. Thus, when a web section is detected having asplice, the strip which is ultimately cut from the web containing thatsplice and the two strips following it are not stacked. The reason thata total of three strips are here involved is because experience hasshown that the initial portion of a roll of web material obtained fromthe web supplier are frequently defective and so it was found desirableto automatically throw away three strip lengths when the first of thesestrips contain a splice.

The web is also pressed against the surface of the drum 55 by extendableand retractable pressure rollers 56a and 56a' forming part of pressureroller assemblies 56 and 56'. The pressure rollers 56a and 56a' arecarried by support structures 56b and 56b' secured to the pistons ofsolenoid valve controlled pneumatic units 56c and 56c'. When thesolenoid controlling this valve is energized, the pneumatic unitsoperate to press the web against the drum 55a. Proximity switches PS-2aand PS-2a' are provided which detects the extended or retracted positionof the associated pressure rollers 56a and 56a'.

As the web leaves the bottom of the driven roller 59, it passes betweena pair of narrow pinch rollers 52a--52a and the driven roller 59. Thepinch rollers 52a--52a form part of a pair of roller assemblies 52--52.The pinch rollers 52a--52a are carried on support structures 52b--52bmovable between extended and retracted positions by pneumatic units52c-52c. The narrow pinch rollers 52a--52a are mounted for lateraladjustment so they can be aligned with the side margins of the foldedweb where they contact the folded over portions of the web. In the caseof the exemplary folded web which in its folded condition has a width of1.125 inches, the width of each of the pinch rollers is preferably 0.75inches so each engages only a portion of the width of each folded web.In contrast, the width of each pressure roller 56a and 56a' and thepressure roller 56a" to be described is at least as wide as the widestfolded web to be received by the equipment, so pressure is appliedthereto over the entire width of the web.

The pinch force of the rollers 52a--52a is adjusted to be approximatelythe same force applied by the pressure rollers 56a and 56a' against theweb passing over the drum 55b. The exact pressure applied by each of therollers 52a--52a, as well as the other rollers, is adjusted by trial anderror to assure the production of a folded web with flat, even folds.The roller assemblies 52--52 have proximity switches likePS-2a"'--PS-2a" (FIG. 8) which detect the retracted or extendedpositions of the associated pinch rollers.

The web leaving the pinch rollers 52a--52a passes between the drivenroller 59 and a pressure roller 56a" of a pressure roller assembly 56"identical to the other pressure roller assemblies 56 and 56'.

The roller 56a" is supported by support structure 56b", connected to thepiston of a solenoid valved controlled pneumatic unit 56c". When thesolenoid controlling the pneumatic unit 56c" is energized, it lowers theroller 56a" to press the web against the driven roller 59. There is aproximity switch PS-2a" which detects the extended or retracted positionof the pressure roller 56a". As the driven roller 59 is driven, the weband the rotatable drum 55 move as a unit.

When any of the proximity switches PS-2a, PS-2a' or PS-2a" indicates theretracted position of the associated roller, the control means 25 (FIG.3) prevents operation of all operating elements of the equipmentillustrated in the drawings.

The pneumatic units 56b, 56b' and 56b" which move the pressure rollers56a, 56a' and 56a" between retracted and extended positions arecontrolled by solenoid operated valves SOL-2, SOL-2' and SOL-2" (seeFIG. 7). The pneumatic unit 52c is similarly controlled by a solenoidoperated valve (not shown). The movement of the drum 55 between itslowered and raised positions is controlled by a solenoid operated valveSOL-3 also shown in FIG. 7. The pneumatic units 52c--52c are similarlycontrolled by solenoid operated valves, not shown.

The pressing of the web against a surface heated to a temperature whichis at or above what is called the annealing temperature of the webmaterial will set the fold made therein by the folding apparatus, as iswell known for many years in the prior art formation of pleats inzig-zag and honeycomb polyester panel materials. It has also been wellknown for many years that to decrease the setting times over ambient aircooling the folded panel is subjected to a cooled environment as it isheld in its desired folded state. U.S. Pat. No. 3,281,516 to Southwichdiscloses the application of pressure and heat to a thermoplasticmaterial, followed by cooling, to permanently fix a folded contour inthermoplastic materials. A preferred condition for setting thepreviously described No. 5040 Ashai folded web material:

Drum surface temperature 370° F.

Contact time of web on drum surface 0.80 seconds.

The resultant normal force applied to web by each of the rollers 56a,56a' --55 pounds.

The web materials which can be handled by the equipment being describedcan have various thicknesses. Since it takes a longer time to heat athicker web than a thinner one, when one changes from a web of onethickness to another, assuming the basic material stays constant, theweb speed is generally increased in inverse proportion to the thicknessof the material. Also, instead of just varying the web speed, one canalso vary the temperature of the drum surface. Thus, if a web ofincreased thickness is to be folded and set, the web speed can bedecreased and the drum surface temperature can be increased somewhat ifdesired to obtain the best results. The temperature to which thematerial is heated is the important objective. That temperature must bebelow the melting temperature of the material and high enough to form aset fold.

To facilitate the cooling of the web moving to a cooling table assembly58, a misting unit 63 may be used to spray a mist of moisture onto theweb as it enters the cooling table assembly 58. This misting unit may beModel No. 100N available from Kool Mist Corporation of Santa Fe Springs,Calif.

The cooling table assembly 58 has an upwardly curved top surface 58aover which the heat set web passes and is stretched by the pullingtension on the web. It is laterally guided over this surface bylaterally adjustable guide walls 58b--58b' (FIG. 9A). The position ofthese guide walls is adjustable by screws 58i and lockable in positionin any suitable way, such as by bolts or screws 58c passing throughthese walls and elongated slots 58d formed in a wall forming the coolingtable 58a, as shown in FIG. 9A. The cooling table surface 58a is cooledin any suitable way, such as by one or more cooling coils 58e.

The cooling table assembly is preferably a structure not shown in thedrawings. It includes the upper surface of an aluminum block withcooling fins on the bottom surface thereof. The bottom of the block islocated in a cooling chamber through which a coolant fluid passes. Inthis form of the invention, the block can be 18" long, 4" wide and 2"high. The cooling fins project 1/4" below the block. There are two suchfins 18" long, 1/8" wide and 1/4" deep.

The web is both pushed by the driven roller 59 onto the cooling tablesurface 58a and pulled over the table under additional tension by adriven roller to be described. This additional driven roller is locatedjust ahead of the cutting means to be described.

When the web material is the exemplary No. 5040 Ashai materialpreviously described, the temperature of the surface of the coolingtable is preferably 40° F. where the web moves at a speed of 250 feetper minute and is pulled and stretched upon the curved cooling tablesurface. In a commercial form of the invention, the cooling table had anoverall length of 18.25" over which substantially the entire length ofwhich the web is stretched. The cooling table surface has a 2" longrecess or opening 58a-1 centered on the peak of the table and abovewhich an adhesive-applying head 60b with a pair of discharge ports60a--60a' is supported. This table opening enables adhesive flowing ordripping from the adhesive-applying means in the absence of a web to becollected by a container (not shown) placed below the recesses. Also,this opening provides for a more consistent deposit of adhesive byproviding a space into which the web can deform slightly as it receivesthe adhesive on the top thereof. Slight irregularities in the tablesurface will not affect the width and thickness of the adhesive deposit.

Since it is desired that the web speeds be substantial for massproduction reasons, it is advantageous to use in addition to the coolingof the cooling table surface 58a and the mister unit 63 added means forcooling the web surface. To this end, a heat dissipation block 58fhaving cooling fins 58f' at the top thereof best shown in FIG. 9D. Thisblock rides upon the full width of the cooling table surface 58a. Theexemplary block has a width of 6", a height of 1/2" and a length alongthe longitudinal axis of the table of 6". Also, the cooling fins 58f'have a width of 1/4" and a height of 1/4. The block 58f is kept frommoving along with the web 131 pulled over the cooling table surface byan abutment pin 58g. A blower 58h blows room temperature air onto thecooling fins 58f'.

For various reasons including the saving of space, the adhesive applyingmeans 16 is mounted above the cooling table surface 58a. It includes apair of adhesive applicator heads 60b13 60b' having a pair of adhesivedischarge ports like 60a' (FIG. 9C) located during adhesive applicationto be just above the surface of the web 13' passing below. As previouslyindicated, it is very important that the correct amount of adhesive isdischarged from the ports to provide both a desired thickness ofadhesive and an adhesive band which is substantially perfectly parallelto the folded over edges of the web. To this end, the commerciallyobtained adhesive applying apparatus which had conventional circulardischarge ports was modified so as to be rectangular in shape, as shownin FIG. 9C. In the case of the exemplary No. 5040 Ashai web materialpreviously disclosed, each discharge port had a length of 4.015" in thedirection of web movement and a width of 5.060". When the dischargepressure applied to the adhesive was 30 bars, this deposited an idealadhesive band of 0.005" thick.

The temperature of the glue and the dispensing thereof are controlled ina well known manner. The entire glue applicator system including theglue applicator heads and the temperature controls therefor arecommercial units sold by Nordson Corporation of 6755 Jimmy CarterBoulevard, Norcross, Ga. 30071 under the model designation PUR204. Thedesired glue temperature, of course, depends upon the particularadhesive which is used. As previously indicated, the preferred adhesiveis obtained from H.B. Fuller Company under order No. NP 2028. For thisadhesive, the desired glue temperature when discharged onto the web is115° F.

The most preferred adhesive applying means is a modification of thatjust described. Instead of utilizing separate heads 60b13 60b' a singlehead (not shown) with two rectangular discharge ports laterally spacedthe same distance as the ports 60a--60a'. The single head is mounted andlockable in any desired lateral position on a single laterally extendingrod to deposit the spaced bands of adhesive at the desired positions onthe web.

When the web leaves the cooling table 58a, it passes between a bottomdriven roller 62 operating at a peripheral speed of 250 feet per minuteand a pressure idler roller 61a of a pressure roller assembly 61 (FIG.11). The pressure roller 61a is supported on a frame 61b movable betweenraised and lowered positions by a suitable pneumatic unit 61c. Therollers 61a and 62 have grooves 61a' and 62' (FIG. 12) to clear theadhesive beads applied to the web. The pneumatic unit 61c is controlledby a suitable solenoid controlled valve unit SOL-4 (FIG. 11). Anexemplary pressure between the pressure roller 61a and the web riding onthe idler roller 62 below is 5 pounds. A proximity switch PS-4 detectsthe retracted, raised position of the pressure roller 61a. The proximityswitch PS-4 then operates to stop or prevent operation of the equipment,as in the case of the other pressure roller associated proximityswitches previously described.

Also shown in FIG. 11 is a solenoid controlled value unit SOL-5 whichcontrols feeding of pneumatic pressure to the misting unit 63, and asolenoid controlled valve unit SOL-6 which controls the pneumatic unit60c to control the up and down movement of the glue applicator head 60b.

Description of Cutting Means 18

The web leaving the pressure roller 61a and the idler roller 62 passesbetween a cutting blade carrying wheel 64 (FIG. 11) and a continuousdriven roller 68. The roller 68 is driven by a suitable motor 69 at aslightly higher (for example, a 5% higher) peripheral speed than thedriven roller 59 mounted above the drum 55a.

For a better description of the cutting apparatus, reference should nowbe made to FIGS. 12, 13, 14 and 14A. The cutting blade carrying wheel 64has a slot 64' which straddles the portion of the web containing thebands of adhesive. It carries a cutting blade 65 with a rounded edge.When the cutting blade 65 is rotated opposite the driven roller 68, itjust barely wipes on the surface thereof. The rounded edge of the blade65 moves at about the same speed as the peripheral speed of the drivenroller 68 and it bites or crushes through the web material cleanly.

The cutting blade carrying wheel 64 is secured to a shaft 66 which inturn connects to the output shaft of a clutch and control unit 67. Thisclutch is preferably one sold by the Warner Corporation of 449 GardnerStreet, South Beloit, Ill. 61086 under model No. CB-6, CW, 24VDC, 3/4".The input shaft 68 to this Warner clutch may be continuously driven by aseparate motor or, as illustrated, by gears 69 and 70, in turn, drivenby a motor driven belt 71 which also drives the shaft on which thedriven roller 68 is mounted. When the clutch unit 67 received an inputsignal, it unlocks its output shaft and rotates the same 360° and thenagain locks the output shaft in place. The cutting blade 65 is shown inFIG. 11 at an initial locked position just in advance of the drivenroller 68. The timing of this input signal is determined by a softwarepulse counter which counts control pulses generated by the drive motorwhich advances the web to the cutting means. When the counter reaches amaximum count which indicates that the web has been moved a givendistance corresponding to the desired length of the strip to be cut fromthe web, this control signal is generated to unlock the output shaft ofthe clutch unit to rotate the blade 65 one resolution to cause the blade65 to cut through the web.

High Speed Conveyor System and Stacking Apparatus

Referring now more particularly to FIGS. 15 and 16, the strip dischargedfrom the cutting means 18 is pushed by driven roller 68 onto the inletend of the first high speed conveyor 20A. The conveyor 20A includes anendless conveyor belt 80 having apertures throughout its length throughwhich suction is drawn. The conveyor belt 80 may have a chain-likeconfiguration with the apertures defined between the links of the chain.The endless belt 80 passes over a sprocket wheel 82 at its inlet end anda drive sprocket wheel 83 at its opposite end (FIG. 18). The sprocketwheel 83 is connected to a shaft 83' which is attached to a belt pulleywheel 84a driven by a belt 84b. The belt 84b is driven by a drive pulley84c driven by a motor 87.

The strips entering the inlet end of the high speed conveyor 20A areguided by laterally adjustable converging guide walls 86--86' (FIG. 15)which diverge to where they are spaced apart a distance equal to thewidth of the strips of material involved.

The upper section 80a of the endless conveyor belt 80 is supplied withsuction by means now to be described. A number of inlet suction tubes88a extending from a suction pump (not shown) open onto the bottom of ahorizontally extending suction conduit 92 (FIG. 17). The suction conduit92 has a number of horizontally extending supports 96 communicating witha vertical chamber 98 extending the length of the conveyor. Thisvertical chamber 98 is defined between two spaced vertical walls94--94'. The upper section 80a of the endless conveyor belt 80 slides ina groove defined between the upper portions of the walls 94--94' and thebelt apertures open onto the top of the chamber 98 so that the suctionpump will cause a suction pressure to hold the strips upon the top ofthe upper section 80a of the belt 80. The bottom section 80b of theendless conveyor belt extends within a groove defined between the lowerends of the walls 94--94'.

In one commercial form of the invention where the strips cut from theweb were about 12 feet, the conveyor belt 80 formed a conveyor pathabout 18 feet long. The conveyor belt 80 in this embodiment of theinvention moved about three times the exemplary 250 feet per minute atwhich the web was advanced to the cutting means 18. The belt 80 deliversthe strip carried thereby to the inlet end of the second higher speedconveyor 20B desirably moving at a somewhat higher speed than theconveyor 20A. The conveyor 20B extends below and along the stackingchamber 22 which, if the strips are 12 feet long, form a conveyor pathat least 12 feet long. It is in practice made much longer than 12 feetto form a discharge end. For example, where the strip length was 12 feetlong, the conveyor 20B moved the web at a speed of 800 feet per minuteand its path length was 14 feet long. These conveyor speeds accommodateda stacking cycle time of 4 seconds.

The conveyor 20B best shown in FIGS. 19B, 20A and 20B include an endlessapertured conveyor belt 80' like the conveyor belt 80 previouslydescribed. This conveyor belt 80' passes around a sprocket wheel 85 atthe inlet end of the conveyor 20B and around a drive sprocket wheel 87at its outlet end. The sprocket wheel 87 is attached to a shaft 87'(FIG. 19B) carrying a pulley wheels 89a--89a', receiving belts 89b--89b'extending around driven pulley wheels 89c--89c. The pulley wheels89c--89c are attached to a shaft 89d driven by a suitable motor 91through a brake clutch 90 controlled by a brake solenoid. When thesolenoid is energized it operates the brake clutch to lock the shaft 89dto stop the conveyor belt 80' when a strip to be stacked is in alignmentwith the stacking chamber pass-through slot previously described in thebottom of the stacking chamber 22.

The passage of the leading and trailing edges of a strip from the end ofconveyer 20A to the inlet end of the conveyor 20B is sensed by acombination light source and light sensor unit PEC-7 so that as thetrailing edge of a strip passes by this sensor a stack-initiating signalis generated which is used to initiate a stacking operation if theequipment is operating in a stacking mode and that strip is to bestacked. The stack-initiating signal effects energization of a solenoidcontrolling the brake clutch 90 to stop movement of the conveyor belt80' after a suitable delay, for reasons previously explained, andinitiate rotation of a cam shaft to be described. This rotation begins astacking operation so that the strip will be fed into the stackingchamber in alignment with the other strips.

The high speed conveyor 20B is mounted on a support structure formovement between a lowered position where the upper section 80a' of theendless conveyor belt is below the bottom of the stacking chamber 22 toa raised position where it moves into the stacking chamber in a mannerto be described.

The high speed conveyor 20B includes a series of suction inlet tubes88a' extending up into a horizontally extending conduit 104 (FIG. 21).The conduit 104 has a series of horizontally spaced ports 105 (FIG. 23A)in the top thereof connecting with a vertical chamber 110 above the samedefined between a pair of horizontally spaced walls 108--108'. The uppersection 80a' of the endless conveyor belt 80' rides in a recess definedby the confronting surfaces of the walls 108--108' so that the suctionforce present in the chamber 110 will draw a strip carried on the uppersection 80a' of the endless conveyor belt 80' onto the top of the belt.The bottom section 80b' of the conveyor belt rides in a recess definedat the bottom ends of the walls 108--108'.

Refer now to FIGS. 20A, 20B and 24 which best illustrate the structurefor the high speed conveyor 20B which supports the conveyor formovement. Secured to the bottom of the suction conduit 104 are a seriesof vertical posts 122 guided for vertical movement in guide brackets124--124 secured to a stationary portion of the support structure. Atthe bottom of each of the posts is a cam follower 126 which rides in acam groove 128a (FIG. 24) in a cam wheel 128 secured to horizontal camshaft 130. The cam shaft 130 carries a number of such cam wheels drivenby a drive motor 132 through a suitable solenoid controlled clutch 132'(see FIG. 20B). In the program flow diagrams, the solenoid controllingthe clutch 132' is referred to as the stacker solenoid.

As the cam shaft 130 rotates, the cam wheels 128 carried thereby rotate.The cam followers 126 at the bottoms of the various vertical posts 122follow the contour of the cam slots 126 to cause the high speed conveyorstructure to move up and down as described. The clutch 132' in one statethereof decouples the motor 132 from the cam shaft 130 and in the otherstate thereof couples the motor 132 to the cam shaft 130. When it isdesired to bypass the stacking chamber, the stacker solenoid is operatedinto its state which operates the clutch to decouple the motor 132 fromthe cam shaft 130, so that the cam shaft remains in a position where thecam follower pins 126 are in the innermost portion of the cam wheelslots 128a. A proximity switch PS-3 shown in FIG. 20B, which responds tothe movement of a cam shaft carried projection 130a' opposite thereto,operates to generate a control signal which, among other things,de-energizes the stacker solenoid to decouple the motor 132 from the camshaft 130 upon completion of a stacking operation. When the cam shaft130 is rotated 180° from this position the cam follower pins 126 are inthe outermost portions of the cam wheel slots where the entire conveyorstructure is in its uppermost position. A proximity switch PS-4 will beoperated by a cam shaft projection 130b moved opposite thereto toindicate this raised condition of the conveyor. A control signal is thengenerated by switch PS-4 to effect control functions which areidentified in the program flow chart of FIG. 25J.

When a stacking operation is called by the program, the stacker solenoidis energized to operate the clutch 132' to couple the drive shaft ofmotor 132 to the cam shaft 130.

Refer now to FIGS. 23A and 23B which discloses the stacking chamberconstruction and the manner in which each strip to be stacked is stackedin the stacking chamber 22 when a stacking operation is carried out. Thestacking chamber 22 is defined between the vertical walls 120--120'spaced apart a distance greater than the width of the strips to bestacked therein. This spacing is adjustable to set up the stackingchamber to receive different strip widths. The walls 120--120' areanchored by screws 118--118' to the upper legs 116b--116b' of spaced,confronting angle members 116--116'. The lower legs 116a--116a' of theangle members are anchored by bolts or screws 115--115' to a stationarysupport structure. The screws 115--115' pass through slots in a pair ofspaced, confronting angle members 112--112' and thread into this supportstructure. The slots permit adjustment of the spacing of the anglemembers 116--116'.

Sandwiched between the legs of the angle members 112--112' and 116--116'are pass-through slot-defining bars 117--117' which are spaced apart adistance less than the width of the strips to be stacked in the stackingchamber. These bars define a longitudinal pass-through slot 119 (FIG.23B) extending the full length of the stacking chamber which is open atits outer ends. The separation distance of the bars 117--117' is, ofcourse, laterally adjustable to accommodate different strip widths. Thisadjustability may be provided by slots in the bars through which theshanks of the screws 115--115' pass. A pass-through slot width of 0.875inches was found suitable for the folded 1.125 inch wide exemplary No.5040 Ashai strip material identified above. The spacing of the stackingchamber walls 120--120' was then adjusted to be 1.165 inches.

The slot 119 is centered below the stacking chamber 22. The definingwalls of the slot-defining bars 117--117' form a floor at the bottom ofthe stacking chamber 22 and above which the strips stacked in thestacking chamber will rest, until they are raised by the force of theupper section of the conveyor belt 88a' rising up into the stackingchamber 22. Before any strips are fed into the stacking chamber, inaccordance with one aspect of the invention, a weight bar 119 may belocated in the stacking chamber, so that it will exert a downward forceon any strips which are moved up into the stacking chamber.

As previously explained, when the trailing edge of a strip passes by thesensor unit PEC-7 located at the end of the first conveyor 20A, a signalis generated by the software which, when a stacking operation isdesired, operates the solenoid controlling the brake clutch 90 (FIG.19B). This operation locks the conveyor belt drive shaft and releasesthe clutch 132' associated with the cam shaft 130, so that the cam shaftis driven by the motor 132. PG,62

The rotation of the cam shaft 130 rotates the cam wheels 128 to raisethe high speed conveyor 20B to a level where the upper section 80a' ofthe endless conveyor belt 80' will carry the strip involved up into thestacking chamber 22, as illustrated in FIG. 23A. The uppermost positionof this conveyor belt section 80a' is shown by dashed lines in FIG. 23A.This strip and the strips immediately above the strip being pushed intothe stacking chamber are raised so that the pressure exerted by theendless conveyor belt in a upward direction and the weight of the weightbar 119 in a downward direction will effect a good adhesive bond betweenthe strips. Because the strip being fed into the stacking chamber isheld in a perfectly horizontal position by the suction force on theupper section 80a' of the endless conveyor belt 80', the strip in anunwrinkled state is adhesively bonded to the strip above it.

As previously indicated, when the upper section 80a' of the endlessconveyor chain is lowered below the pass-through slot 119, thebottommost strip just delivered to the stacking chamber remains in thestacking chamber as the belt moves downward through the slot.

Program Flow Diagrams of FIGS. 25A-25G

The program flow diagrams of FIGS. 25A-25G illustrate the manner inwhich the software used with the present invention responds to varioussensor and manual switch conditions indicated therein. These flowdiagrams are, for the most part, self-explanatory. They include, inaddition to a description of the stacking mode of operation of theinvention, other modes of operation used in setting up or testing theequipment shown, as well as a splice bypass mode when a splice isdetected. It should be understood that where reference is made in thesediagrams to setting a marker in memory to effect a given mode ofoperation this implies also that the marker previously set to obtain theopposite mode of operation is removed from memory automatically. Also,the various point-indicating letters appearing in these diagramsindicate common points to which the similar identified points of thevarious figures are connected to complete one overall program flowchart. Also, many of the questioned functions are determined by theoperation of manual switches.

It should be further understood that the present invention is notlimited to software control since hardware control elements canobviously be substituted for software indicated control elements.

Modified Stacking Chamber Construction and Associated Quality Controland Box-Packing Station

As previously indicated, in the preferred from of the invention, tomaximize production efficiency and reliability, the stacking chamberstation is modified in the manner illustrated in FIG. 26. As thereshown,the forward stacking chamber-forming wall 120' shown in FIG. 23 isreplaced by a wall 120a' which extends first upward and then curvesdownwardly to form in a forwardly and downwardly inclining productquality monitoring wall portion 120a'-1. The inclined wall portion120a'-1, in turn, terminates in a downwardly extending front wallportion 120a'-2. This modified wall 120a' is preferably made of a whitetranslucent material. The inclined monitoring wall portion 120a'-1 formsa quality control translucent window behind which are mounted florescentlamps 130 which back-light the wall portion 120a'-1.

The rear stacking chamber-forming wall 120 is modified to form a wall120a which extends upwardly and then curves slightly to the left toconfront the beginning of the curved portion of wall 120a', to define anexit aperture of the stacking chamber which directs the stacked stripsonto the inclined monitoring wall portion 120a'-1.

The downwardly extending wall portion 120a'-2 terminates along the frontface of a rear vertical packing box-receiving wall 132. Confronting thewall 132 is a similar wall 132' which defines with the wall 132 anopen-top packing box-receiving passageway 134. This passageway receivesa narrow rectangular packing box 136 having a top flap 136' which whenopened exposes an entryway into the box 136 which can hold, for example,as many as 600 unexpanded strips of material which is to constitute theproduct shipped to the honeycomb panel fabricator. The strips areautomatically guided into the box 136 by the wall portion 120a'-2. Thequality control station illustrated in FIG. 26 is useful both whenseparable stacks of strips or a single continuous stack of securedtogether strips are produced in the stacking chamber.

Honeycomb panel material from which the strips involved are made arefabricated with different surface coloration or other ornamentation.Certain colors and surface ornamentations sometimes come from thematerial supplier with substantial defects than strips which areuncolored or ornamented differently therefrom. Where a very small amountof defective material is expected to be produced in the stackingchamber, build up of separable stacks in the stacking chamber ispreferred. However, if a substantial amount of defective material isanticipated, a continuous build up of secured together stacks ispreferred, to enable the quality control person who examines the stripmaterial passing over the inclined monetary wall portion 120a'-1 to cutout the defective strips or group of strips before they are directedinto the box 136. This cut-out operation is preferably achieved by theoperator without stopping the equipment. He would use a knife or othersuitable cutting edge tool to severe the defective strips from the stackof strips involved.

Scope of Claims

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the broader aspects of theinvention. Also, it is intended that broad claims not specifying detailsof a particular embodiment disclosed herein as the best modecontemplated for carrying out the invention should not be limited tosuch details. Furthermore, while, generally, specific claimed details ofthe invention constitute important specific aspects of the invention inappropriate instances even the specific claims involved should beconstrued in light of the doctrine of equivalents.

We claim:
 1. A method of producing one or more individual stacks offlat, expandable tubular strips forming an expandable honeycomb panel,each stack to comprise N secured-together such strips of a length L themethod comprising the steps of:providing a continuous flexible sheet ofmaterial; forming a flat, expandable tubular web from said continuousflexible material from which said strips are to be cut, stacked andsecured together, said web having a number of major sections along itslength, each major section having a portion comprising N-1 to-be-stackedsegments each having a length L, a first to be stacked segment of alength L preceding said N-1 segments, and a not-to-be stacked portionbetween first to-be stacked segment and said N-1 segments, saidnot-to-be stacked portion having a not-to-be stacked front margin, saidN-1 to-be-stacked segments including a last segment having an endmargin, and said first to be stacked segment having a firstto-be-stacked front margin; moving said web first to anadhesive-applying station having at least one adhesive applying unitwhich is adapted to discharge adhesive down upon the top of said web andwhich is to be turned on and off to initiate adhesive flow and adhesiveflow interruption periods respectively; turning said at least oneadhesive applying unit on when the not-to-be stacked front margin ofeach major web section passes thereby so that the consistency of theadhesive reaches a desired level by the time said N-1 segments of eachweb section passes thereby; initiating the turn-off of said at least oneadhesive applying unit at a point in time so that it is turned offcompletely at least when the first to-be-stacked front margin of saidfirst-to-be stacked segment of the web passes thereby and after the endmargin of the last segment of said N-1 segments of the web passesthereby; moving the adhesive coated web to a cutting station where thefirst to-be-stacked segment and N-1 to-be-stacked segments of the webare transversely and sequentially cut into N individual flat, expandabletubular cut strips each of a length L, and where the not-to-be stackedportions of the web are transversely and sequentially cut into at leasta single not-to-be stacked strip; delivering said strips cut from saidfirst to-be-stacked segments and N-1 to-be-stacked segments of the webto a stacking station where the strips are stacked and pushed againsteach other to adhere the strips together forming an expandable honeycombpanel; and delivering the strips cut from said not-to-be-stackedportions of the web to a delivery point where these strips are notstacked.
 2. A method of producing one or more individual stacks of flat,expandable tubular strips forming an expandable honeycomb panel, eachstack to comprise N secured-together such strips of a length L, themethod comprising the steps of:providing a continuous flexible sheet ofmaterial; forming a flat, expandable tubular web from which said stripsare to be cut, stacked and secured together, said web having a number ofmajor sections along its length, each major section having a portioncomprising N-1 to-be-stacked segments each having a length L, afirst-to-be-stacked segment of a length L preceding said N-1 segments,and a not-to-be-stacked portion preceding said first-to-be-stackedsegment; continuously moving said web first to an adhesive-applyingstation having at least one adhesive applying unit which dischargesadhesive down upon the top of said web and which is to be turned on andoff to initiate adhesive flow and adhesive flow interruption periodsrespectively; initiating the turn off of said at least one adhesiveapplying unit when said not-to-be-stacked portion of each major websection passes thereby so that the unit is completely turned off whensaid first-to-be-stacked segment of each web section passes thereby andturning said at least one adhesive applying unit on at a point in timeso that the adhesive flows with a desired consistency; continuouslymoving the adhesive-coated web to a cutting station where the firstto-be-stacked segment and the N-1 to-be-stacked segments of the web aretransversely and sequentially cut into N individual flat, expandabletubular cut strips each of a length L, and where the not-to-be-stackedportions of the web are transversely and sequentially cut into at leasta single not-to-be-stacked strip; delivering said strips cut from saidfirst to-be-stacked segments and N-1 to-be-stacked segments of the webto a stacking station where the strips are stacked and pushed againsteach other to stack and adhere the strips together forming an expandablehoneycomb panel; and delivering the strips cut from saidnot-to-be-stacked portions of the web sequentially to a delivery pointwhere these strips are not stacked.